开发技术学习

function msubstr($str, $start=0, $length, $charset="utf-8", $suffix=true) { if(function_exists("mb_substr")){ $slice = mb_substr($str, $start, $length, $charset); $strlen = mb_strlen($str,$charset); }elseif(function_exists('iconv_substr')) { $slice = iconv_substr($str,$start,$length,$charset); $strlen = iconv_strlen($str,$charset); if(false === $slice) { $slice = ''; } }else{ $re['utf-8']   = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/"; $re['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/"; $re['gbk']    = "/[x01-x7f]|[x81-xfe][x40-xfe]/"; $re['big5']   = "/[x01-x7f]|[x81-xfe]([x40-x7e]|xa1-xfe])/"; preg_match_all($re[$charset], $str, $match); $slice = join("",array_slice($match[0], $start, $length)); $strlen = strlen($str); } if ($strlen > $length && $suffix){ return $slice.'...'; }else{ return $slice; } //    return $suffix ? $slice.'...' : $slice; }